光纤器件Opticallynonreciprocaldevicesprovidecriticalfunctionalitiessuchaslightisolationandcirculationinintegratedphotoniccircuitsforopticalcommunicationsandinformationprocessing,buthavebeendifficulttoachieve.Byexploringgain-saturationnonlinearity,wedemonstrateon-chipopticalnonreciprocitywithexcellen